CA1317050C - Easily peelable semiconductive resin composition - Google Patents
Easily peelable semiconductive resin compositionInfo
- Publication number
- CA1317050C CA1317050C CA000577055A CA577055A CA1317050C CA 1317050 C CA1317050 C CA 1317050C CA 000577055 A CA000577055 A CA 000577055A CA 577055 A CA577055 A CA 577055A CA 1317050 C CA1317050 C CA 1317050C
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- Prior art keywords
- vinyl acetate
- parts
- tion
- easily peelable
- ethylene
- Prior art date
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Classifications
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L23/00—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers
- C08L23/02—Compositions of homopolymers or copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond; Compositions of derivatives of such polymers not modified by chemical after-treatment
- C08L23/04—Homopolymers or copolymers of ethene
- C08L23/08—Copolymers of ethene
- C08L23/0846—Copolymers of ethene with unsaturated hydrocarbons containing other atoms than carbon or hydrogen atoms
- C08L23/0853—Vinylacetate
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08K—Use of inorganic or non-macromolecular organic substances as compounding ingredients
- C08K3/00—Use of inorganic substances as compounding ingredients
- C08K3/02—Elements
- C08K3/04—Carbon
-
- H—ELECTRICITY
- H01—ELECTRIC ELEMENTS
- H01B—CABLES; CONDUCTORS; INSULATORS; SELECTION OF MATERIALS FOR THEIR CONDUCTIVE, INSULATING OR DIELECTRIC PROPERTIES
- H01B1/00—Conductors or conductive bodies characterised by the conductive materials; Selection of materials as conductors
- H01B1/20—Conductive material dispersed in non-conductive organic material
- H01B1/24—Conductive material dispersed in non-conductive organic material the conductive material comprising carbon-silicon compounds, carbon or silicon
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2203/00—Applications
- C08L2203/20—Applications use in electrical or conductive gadgets
- C08L2203/202—Applications use in electrical or conductive gadgets use in electrical wires or wirecoating
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L2205/00—Polymer mixtures characterised by other features
- C08L2205/03—Polymer mixtures characterised by other features containing three or more polymers in a blend
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- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L51/00—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers
- C08L51/06—Compositions of graft polymers in which the grafted component is obtained by reactions only involving carbon-to-carbon unsaturated bonds; Compositions of derivatives of such polymers grafted on to homopolymers or copolymers of aliphatic hydrocarbons containing only one carbon-to-carbon double bond
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08L—COMPOSITIONS OF MACROMOLECULAR COMPOUNDS
- C08L91/00—Compositions of oils, fats or waxes; Compositions of derivatives thereof
- C08L91/06—Waxes
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Dispersion Chemistry (AREA)
- Spectroscopy & Molecular Physics (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Conductive Materials (AREA)
- Pigments, Carbon Blacks, Or Wood Stains (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
An easily peelable semiconductive resin composi-tion comprising 100 parts by weight of ethylene-vinyl acetate copolymer-based polymer component, 1 to 20 parts by weight of waxy aliphatic hydrocarbon, and 50 parts by weight or more of furnace carbon black having an arithmetic mean particle size of 25 to 40 mµ, iodine adsorption of 40 to 60 mg/g, and DBP oil absorption (by JIS A method) of 120 to 150 ml/100 g.
An easily peelable semiconductive resin composi-tion comprising 100 parts by weight of ethylene-vinyl acetate copolymer-based polymer component, 1 to 20 parts by weight of waxy aliphatic hydrocarbon, and 50 parts by weight or more of furnace carbon black having an arithmetic mean particle size of 25 to 40 mµ, iodine adsorption of 40 to 60 mg/g, and DBP oil absorption (by JIS A method) of 120 to 150 ml/100 g.
Description
~3~7~
`
EASILY PEELABLE
SEMICONDUCTIVE RESIN COMPOSITIOM
FIELD OF T~E INVENTION
This invention relates to a semiconductive resin composition suitably used for the formation of the external semiconductive layer of the plastic-insulated electric power cables, especially to an easily peelable semiconductive resin composition which can form an ex ternal semiconductive layer improved in both adhesion to and peeling from the crosslinked polyethylene insulator.
BACKGROUND OF TEIE INVE~TION
Generally, the external semiconductive layer of the plastic-insulated electrio cables, particularly o~
those insulated with a crosslinked polyethylene, is formed by extrusion. It is necessary for the external semicon-ductive laye~ to tightly adhere to the crosslinked poly-ethylene insulator in order to avoid generation of corona discharge. There is also a demand, on the other hand, that the external semiconductive layer should be easily removed in the case of terminal treatment of the cable without giving any damage to the insulator. Accordingly, there is a demand for an external semiconductive layer which efficiently adheres in the normal state but which is 25; easily peeled in the case of ~eed.
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1 Such a semiconductive layer can be obtained by using, as a base material, a polymer having no affinity with the crosslinked polyethylene insulator. Convention-ally used base material is an ethylene-vinyl acetate copolymer.
To attain satisfactory peeling properties, however, those with high vinyl acetate concentration (e.g., with 45 % by weight or higher) or a vinyl chloride-grafted copolymer should be used. Such semiconductive layers result in poor thermal resistance and mechanical strength, and al50, a satis~actory extrusion workability was not obtained.
SUMMARY OF THE INVENTION
The present invention have been made to solve the aforesaid problems. Thus it is an object of the present invention to provide an easily peelable semiconductive resin composition wlth improved peeling property, thermal resistance~ and mechanical properties, as well as excel-lent extrusion workability.
The semiconductive resin composition of the presPnt invention comprises 100 parts by weight of ethylene-vinyl acetate copolymer-based polymer component, 1 to 20 parts by weight of waxy aliphatic hydrocarbon, and 50 parts by weight or more of furnace carbon black having an arithmetic mean particle size of 25 to 40 m~, iodine ' . .
~' 13~705~
1 absorption of 40 to 60 mg/g, and DBP oil absorption (by JIS A method) of 120 to 150 me/100g.
The polymer component in the present invention may be the ethylene vinyl acetate copolymer alone or a combi-nation thereof with another polymer.
The ethylene-vinyl acetate copolymer as the base polymer is not particularly limited, however, it is pre-ferable that the vinyl acetate cont~nt is in the range of 20 to 55% by wei~ht. When the content is less than 20% by weight, a satisfactory peeling property is not achieved, and when the content exceeds 55% by weight, the mechanical strength of the semiconductive layer tends to decrease.
One of the pre~erable polymer components in the present invention is the blend of the ethylene-vinyl acetate copolymer and an aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer. This polymer component may further improve the peeling property.
The aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer to be used in the present invention is a copolymer obtained by graft-copolymerization of aromatic vinyl monomers such as styrene, methyl styrene, and a-methyl styrene~ to an ethylene-vinyl acetate copolymer rontaining 20% by weight or~more of vinyl acetate.
The content o~ the aramatic vinyl monomer to be incorporated into the aromatic vinyl monomer-modified ''`^': .
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1 ethylene-vinyl acetate copolymer i5 preferably from 5 to 60% by weight. Further, the polymer component should desirably contain 95 to 50% by weight of ethylene-vinyl acetate copolymer and 5 to 50% by weight of aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer. The aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer of less than 5% by weight has little contri-bution to the peeling property, and that of more than 50%
by weight decreases the mechanical strength of the semi-conductive layer.
A chief feature of the present invention resides in that a waxy aliphatic hydrocarbon and a special furnace carbon black having an arithmetic mean particle size of 25 to 40 m~, an iodine adsorption of 40 to 60 mg/g, a DBP oil absorption (by JIS A method) of 120 to 150 m~/lO0 g, are used together. This gives a synergetic effect resulting in an improved peeling property and an improved extrusion workability due to the lowered viscosity.
Examples of waxy aliphatic hydrocarbons include paraffine wax, microcrystalline wax, and petrolatum, all of which normally have a molecular weight of l,OOo or less.
The amount of the waxy aliphatic hydrocarbon to be incorporated is restricted to 1 to 20 parts by weight per lO0 parts by weight of the polymer component, wherein a 13~7~
1 content of less than 1 part by weight is insufficient to improve peeling properties and extrusion workability, whereas a content exceeding 20 parts by weight damages thermal resistance~
The arithmetic mean particle size of the special furnace carbon black in the present invention is obtained by electron microscopic method. When particles smaller than 25 m~ are used, extrusion workability is damaged by increasing viscosity. When particles exceeding 40 m~u are used, sufficient conductivity cannot be obtained An iodine adsorption of- less than 40 mg/g gives insuf~icient conductivity and that in excess of 60 mg/g increases the viscosity of the composite and deteriorates the extrusion workability.
DBP oil absorption is measured by JIS A method.
When it is lower than 120 me/100 g, conductivity obtained is not high enough, and a value higher than 150 me/loo g increases the viscosity of the composition and adversely affects the extrusion workability.
The special furnace carbon black should be added in an amount of 50 parts by weight or more per 100 parts by weight of the polymer component. If the amount is less than this limit, no satisfactory conductivity is obtained.
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1 Acetylene black may be used together with the above sperial furnace carbon black so far as the viscosity of the composition is not increased to a large extent.
Lubricants and antioxidants may be added in addition to the aforesaid components. Aliphatic alcohols, fatty acids, esters of fatty acids, metal salts of fatty acids, fatty acid amides, and the like are the examples of the lubricants. Those may be used singly or in combina-tions of two or more thereof.
Specific antioxidants include thiobisphenols, alkylidenebisphenols, alkylphenols, hydroxybenzyl com-pounds, aminophenols, hydroxyphenylpropionates, secondary aromatic amines, thioethers, phosphites, phosphonites, etc. These may be used indepenciently or in combinations of two or more.
The composition of the present invention may be crosslinked. Organic peroxides are generally used for a crosslinking agent in the present case. Dicumyl per-oxides, 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,2-dimethyl-2/5-di(tert-butylperoxy)hexine-3 are specific examples for dialkyl peroxides suitable for use as the crosslinking agent.
The present invention is now illustrated in greater detail with reference to nonlimiting Examples and ~3~7~
1 Comparative Examples. In these examplesl all percents and parts are by weight unless otherwise indicated.
EXAMPLES
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The indicated components were kneaded with a Bambury mixer to give the compositions for Examples 1 to 10 and Comparative Examples 1 to 10 shown below. The thus-obtained mixtures each was fed to a 65-mm extruder to form a 0.7 mm thick external semiconductive layer together with a 0.7 mm thick internal semiconductive layer and a 4 mm thick crosslinked polyethylene insulater on an annealed copper twisted wire conductor having a cross sectional area of 150 mm2 by extrusion coating using a common head.
Then, the coated product was heated at 230C for crosslinking to manufacture an electric power cable insulated with a crosslinked polyethylene. The cross-linked polyethylene insulating layer was formed using a composition comprising 100 parts by weight of low density polyethylene (having a density of 0.920 g/cm3 and a melt index of 1.0 g/10 min), 2.5 parts by weight of dicumyl 20 ~ peroxide as the crosslinking agent and 0.25 parts by weight of 4,4'-thio-bis(3-methyl-6-tert-butylphenol). The temperature of the extruder was set in the direction from the feeding zone to the metering zone, as follows:
Cl=100C, C2=110C, C3=115C, and the die temperature of 120C.
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Ethylene-vinyl acetate copolymer 100 parts (containing 19~ of vinyl acetate;
with melt index of 2.5 g/lO min) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6 tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)ben2ene 0.5 parts Furnace carbon black (with arithmetic mean 60 parts particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 m~/100 g) Ethylene-vinyl acetate copolymer 100 parts (containing 25% of vinyl acetatei with meIt index of 3.0 g/10 min) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 part :
1,3-Bis(tert-butylperoxyisopropyl)benzene o.~ parts Furnace carbon black: (with arithmetic mean 60 parts particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 m~/lOO g) : .
Ethylene-vinyl acetate copolymer 100 parts (containing 28% of vinyl acetate;
with melt index of 6.0 g~10 min) ;` :
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1 Paraffin wax (melting point of 57.3C) 1 part 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) l part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~, iodine adsorption of 51 mg/g; and DBP oil absorption of 124 me/100 g) 1o EXAMPLE 4 Ethylene-vinyl acetate copolymer lO0 parts (containing 28% of vinyl acetate;
with melt index of 6.0 g/lO min) Paraffin wax (melting point of 57.3C) 10 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) l part 1,3-Bis(tert-butylperoxyisopropyl)ben~ene 0.5 parts Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 m~/lO0 g) EX~MPLE 5 Ethylene-vinyl acetate copolymer lO0 parts :(containing 28~ of vinyl acetate;
with melt index of 6.0:g/lO min) Paraffin wax (melting point of 57.3C) 20 parts 4,4'-Thi.o-bis(3-methyl-6-tert-butylphenol) 1 part 1, 3-Bis ( tert-butylperoxyisopropyl)benzene 0.5 parts . .
.
i3~7~0 1 Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 m~/100 g) Ethylene-vinyl acetate copolymer80 parts (containing 28~ of vinyl acetate;
with melt index of 6.0 g/10 min) Styrene-modified ethylene-vinyl acetate20 parts copolymer (containing 50% of styrene and 17~-of vinyl acetate) Paraffin wax (melting point of ~7.3C)5 parts 4,4' ~Thio-bis ~ 3~methyl~6~tert~butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 m~/100 g) Ethylene-vinyl acetate copolymerB0 parts (containing 28% of vinyl acetate;
with melt index of 6.0 g/10 min) Styrene-modified ethylene-vinyl acetate20 parts copolymer ~containing 50~ of styrene and 17~ of vinyl acetate) Paraffin wax (melting point of 57.3C)5 parts 131 7 ~ 3 ~
1 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic mean 60 parts particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 m~/100 g) Acetylene black (with arithmetic mean 20 parts particle size of 42 m~; iodine adsorption of 70 mg/g, and DBP oil absorption of 145 m~/100 g) Ethylene--vinyl acetate copolymer 60 parts (containing 28% of vinyl acetate;
with melt index of 6 g/10 min) Styrene-modified ethylene-vinyl acetate 40 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) Paraffin wax ~melting point of 57.3C) 5 parts 4,4'-Thio-his(3-methyl-6-tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl~benzene 0.5 parts Furnace carbon black (~ith arithmetic 80 parts mean particle size of 30 m~l; iodine adsorption of 53 mg/g; and DBP oil absorption of 13~ m~/lOOg) Ethylene-vinyl acetate copolymer 100 parts (containing 33% o~ vinyl acetate;
with melt index of 1 g/10 min) ~ 3 ~
1 Microcrystalline wax ~melting point 80C) 10 parts 4,4'-Thio-bis(3-methyl-6 tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP
oil absorption of 133 me/loo g) Ethylene-vinyl acetate copolymer 80 parts (containing 33% of vinyl acetate; with melt index of 1 g/10 min) 15. Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) ~icrocrystalline wax (melting point 10 parts of 80C) 4,4'-Thio-bis(3-methyl-6-tert~butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption o~ 133 me/100 g) COMPARATIVE EX~MPLE 1 ~ :
Ethylene-vinyl acetate copolymer 100 parts (containing 60% of vinyl acetate;
with melt index of l0 to 20 g/10 min) :
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1 4,4'-Thio-bis~3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Acetylene black ~with arithmetic 70 parts mean particle size of 42 m~; iodine adsorption of 70 mg/g; and DBP oil absorption of 145 me/loo g) Vinyl chloride-Ethylene-vinyl acetate 100 parts terpolymer (containing 21% of vinyl acetate and 25% of vinyl chloride) 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Acetylene black (with arithmetic 70 parts mean particle size of 42 m~; iodine adsorption of 70 mg/g; and DBP oil absorption of 145 me/100 9 ) COMPARATIVE EXl~MPLE 3 Ethylene-vinyl acetate copolymer 100 parts (containing 28% of vinyl acetate;
with melt index of 6 g/10 min) Paraffin wax (melting point of 57.3C) 0.7 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-~is(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic ~0 parts mean particle size o~ 35 m~; iodine adsorption of 51 mg/g; and D~P oil absorption oE 124 me/100 g) ~ 3~5~
Ethylene-vinyl acetate copolymer100 parts (containing 28~ of vinyl acetate;
with melt index of 6 g/10 min) Paraffin wax (melting point of 57.3C) 25 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 me/100 g) Ethylene-vinyl acetate copolymer80 parts (containing 28~ of vinyl acetate;
with melt index of 6 g/10 min) ~ Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) Para~in wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxylsopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 45 parts mean particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 mejlOO g) ~3~7~
Ethylene-vinyl acetate copolymer 100 parts (containing 33% of vinyl acetate;
with melt index of 1 y~10 min) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size o~ 22 m~; iodine adsorption of 104 mg/g; and DBP oil absorption of 129 me/100 g) Ethylene-vinyl acetate copolymer 100 parts (containing 33% of vinyl acetate;
with melt index o~ 1 g/10 min) Paraffin wax (melting point of 57.3C) 5 parts ; . 4,4'-Thio-bis~3-methyl-6-tert-butylphenol)1 parts ~ 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arlthmetic 80 parts mean particle size of 29 m~; iodine adsorption of 70 mg/g; and DBP oil absorption of 127 me/100 g) Ethylene-vinyl acetate copolymer 100 parts (containing 33~ of vinyl acetate;
with melt index of 1 g/10 min) 13~7~
Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 34 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 103 me/100 g) Ethylene-vinyl acetate copolymer 80 parts (containing 33% of vinyl acetate;
~with melt index of 1 ~/10 min) Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing so% of styrene and 17~ of vinyl acetate) Para~fin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 30 m~; iodine adsorption of 220 mg/g; and DBP oil absorption of 178 me/100 g) Ethylene-vinyl acetate copolymer 80 parts (containing 33% of vinyl acetate;
with melt index of 1 g/10 min) ?
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1 Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 43 m~; iodine adsorption of 44 mg/g; and DBP oil absorption of 115 m~/100 g) The compositions given above and the cables prepared using thereof were evaluated and the results are given in Table 1.
Evaluation were made according to the following.
Peel strenqth: Force necessary to peel the outer semiconductive layer off the cable was measured at room temperature according to the AEIC-CS5-82 standard.
Volume resistivity: Measured according to the AEIC-CS5-82 standard.
Tensile strenqth: The semiconductive layer peeled off the cable was measured following the JIS C-3005 standard. Those having the tensile strength of 1.0 kg/mm2 or more were evaluated 'good' and those lower than 1.O kg/mm2 were evaluated 'poor'.
1 Heat aqinq resistance; The semiconductive layer peeled off the cable was aged in a gear-oven aging tester at 135C for 7 days according to the IEC standardized method. Those maintaining both tensile strength and elongation in the range from 75% to 125~ of the initial values were evaluated 'good' and those showing values out of the above were evaluated 'poor'~
Mooney viscosity (MLl~4): Evaluations were made on semiconductive compositions at 120C. Those having values of 50 or less had good extrusion workability.
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r~ ~ ~ ~ ~ ~ E~ ~ ~ ~ ~ l~o o ~o ~o ~o ~o ~o o _ _ _ _ __ - - " I" ~ '~ " " " '~ '' _ _ _ _ _ _ _ _ _ _ _ ~3~7(3~
1 The samples of Example 1 to 10 of the present invention on the whole had good peeling strength, volume resistivity, mechanical stren~th, thermal resistance, and viscosity for the composition, except for the sample using an ethylene-vinyl acetate copolymer containing 19% by weight of vinyl acetate which showed a somewhat increased peeling strength.
Comparative Examples 1 and 2 used an ethylene-vinyl acetate copolymer containing 60% by weight of vinyl acetate and a vinyl chloride-ethylene-vinyl acetate terpolymer, respectively. In these cases, both mechanical strength and thermal resistance are insufficient.
Moreover, Mooney viscosity was so high that extrusion workability was deteriorated. Comparative Example 3 used less paraffin wax than the limit defined in the present invention. In such a case, peeling strength was increased and also the extrusion workability is somewhat damaged. Comparati~e Example 4, ~n the contrary, used more paraffin wax than the limit o~ the invention. In this case/ the heat aging resistance is insufficient.
Comparative Example 5 used furnace carbon black in an amount less than the limit of the present invention that the volume resistivity is too increased. Comparative Examples from 6 to 10 used furnàce carbon black in an amount out of the content range limited in the present _4 ' .
.
-~ ' 1 invention that volume resistivity or extrusion workability was deteriorated despite the good peeling property.
While the invention has been described in detail and with reEerence to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
.
`
EASILY PEELABLE
SEMICONDUCTIVE RESIN COMPOSITIOM
FIELD OF T~E INVENTION
This invention relates to a semiconductive resin composition suitably used for the formation of the external semiconductive layer of the plastic-insulated electric power cables, especially to an easily peelable semiconductive resin composition which can form an ex ternal semiconductive layer improved in both adhesion to and peeling from the crosslinked polyethylene insulator.
BACKGROUND OF TEIE INVE~TION
Generally, the external semiconductive layer of the plastic-insulated electrio cables, particularly o~
those insulated with a crosslinked polyethylene, is formed by extrusion. It is necessary for the external semicon-ductive laye~ to tightly adhere to the crosslinked poly-ethylene insulator in order to avoid generation of corona discharge. There is also a demand, on the other hand, that the external semiconductive layer should be easily removed in the case of terminal treatment of the cable without giving any damage to the insulator. Accordingly, there is a demand for an external semiconductive layer which efficiently adheres in the normal state but which is 25; easily peeled in the case of ~eed.
. . . ~
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l3~7a~
1 Such a semiconductive layer can be obtained by using, as a base material, a polymer having no affinity with the crosslinked polyethylene insulator. Convention-ally used base material is an ethylene-vinyl acetate copolymer.
To attain satisfactory peeling properties, however, those with high vinyl acetate concentration (e.g., with 45 % by weight or higher) or a vinyl chloride-grafted copolymer should be used. Such semiconductive layers result in poor thermal resistance and mechanical strength, and al50, a satis~actory extrusion workability was not obtained.
SUMMARY OF THE INVENTION
The present invention have been made to solve the aforesaid problems. Thus it is an object of the present invention to provide an easily peelable semiconductive resin composition wlth improved peeling property, thermal resistance~ and mechanical properties, as well as excel-lent extrusion workability.
The semiconductive resin composition of the presPnt invention comprises 100 parts by weight of ethylene-vinyl acetate copolymer-based polymer component, 1 to 20 parts by weight of waxy aliphatic hydrocarbon, and 50 parts by weight or more of furnace carbon black having an arithmetic mean particle size of 25 to 40 m~, iodine ' . .
~' 13~705~
1 absorption of 40 to 60 mg/g, and DBP oil absorption (by JIS A method) of 120 to 150 me/100g.
The polymer component in the present invention may be the ethylene vinyl acetate copolymer alone or a combi-nation thereof with another polymer.
The ethylene-vinyl acetate copolymer as the base polymer is not particularly limited, however, it is pre-ferable that the vinyl acetate cont~nt is in the range of 20 to 55% by wei~ht. When the content is less than 20% by weight, a satisfactory peeling property is not achieved, and when the content exceeds 55% by weight, the mechanical strength of the semiconductive layer tends to decrease.
One of the pre~erable polymer components in the present invention is the blend of the ethylene-vinyl acetate copolymer and an aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer. This polymer component may further improve the peeling property.
The aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer to be used in the present invention is a copolymer obtained by graft-copolymerization of aromatic vinyl monomers such as styrene, methyl styrene, and a-methyl styrene~ to an ethylene-vinyl acetate copolymer rontaining 20% by weight or~more of vinyl acetate.
The content o~ the aramatic vinyl monomer to be incorporated into the aromatic vinyl monomer-modified ''`^': .
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.
~3~7o~
1 ethylene-vinyl acetate copolymer i5 preferably from 5 to 60% by weight. Further, the polymer component should desirably contain 95 to 50% by weight of ethylene-vinyl acetate copolymer and 5 to 50% by weight of aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer. The aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer of less than 5% by weight has little contri-bution to the peeling property, and that of more than 50%
by weight decreases the mechanical strength of the semi-conductive layer.
A chief feature of the present invention resides in that a waxy aliphatic hydrocarbon and a special furnace carbon black having an arithmetic mean particle size of 25 to 40 m~, an iodine adsorption of 40 to 60 mg/g, a DBP oil absorption (by JIS A method) of 120 to 150 m~/lO0 g, are used together. This gives a synergetic effect resulting in an improved peeling property and an improved extrusion workability due to the lowered viscosity.
Examples of waxy aliphatic hydrocarbons include paraffine wax, microcrystalline wax, and petrolatum, all of which normally have a molecular weight of l,OOo or less.
The amount of the waxy aliphatic hydrocarbon to be incorporated is restricted to 1 to 20 parts by weight per lO0 parts by weight of the polymer component, wherein a 13~7~
1 content of less than 1 part by weight is insufficient to improve peeling properties and extrusion workability, whereas a content exceeding 20 parts by weight damages thermal resistance~
The arithmetic mean particle size of the special furnace carbon black in the present invention is obtained by electron microscopic method. When particles smaller than 25 m~ are used, extrusion workability is damaged by increasing viscosity. When particles exceeding 40 m~u are used, sufficient conductivity cannot be obtained An iodine adsorption of- less than 40 mg/g gives insuf~icient conductivity and that in excess of 60 mg/g increases the viscosity of the composite and deteriorates the extrusion workability.
DBP oil absorption is measured by JIS A method.
When it is lower than 120 me/100 g, conductivity obtained is not high enough, and a value higher than 150 me/loo g increases the viscosity of the composition and adversely affects the extrusion workability.
The special furnace carbon black should be added in an amount of 50 parts by weight or more per 100 parts by weight of the polymer component. If the amount is less than this limit, no satisfactory conductivity is obtained.
~5 , ~ , , .
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~317~
1 Acetylene black may be used together with the above sperial furnace carbon black so far as the viscosity of the composition is not increased to a large extent.
Lubricants and antioxidants may be added in addition to the aforesaid components. Aliphatic alcohols, fatty acids, esters of fatty acids, metal salts of fatty acids, fatty acid amides, and the like are the examples of the lubricants. Those may be used singly or in combina-tions of two or more thereof.
Specific antioxidants include thiobisphenols, alkylidenebisphenols, alkylphenols, hydroxybenzyl com-pounds, aminophenols, hydroxyphenylpropionates, secondary aromatic amines, thioethers, phosphites, phosphonites, etc. These may be used indepenciently or in combinations of two or more.
The composition of the present invention may be crosslinked. Organic peroxides are generally used for a crosslinking agent in the present case. Dicumyl per-oxides, 1,3-bis(tert-butylperoxyisopropyl)benzene, 2,2-dimethyl-2/5-di(tert-butylperoxy)hexine-3 are specific examples for dialkyl peroxides suitable for use as the crosslinking agent.
The present invention is now illustrated in greater detail with reference to nonlimiting Examples and ~3~7~
1 Comparative Examples. In these examplesl all percents and parts are by weight unless otherwise indicated.
EXAMPLES
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The indicated components were kneaded with a Bambury mixer to give the compositions for Examples 1 to 10 and Comparative Examples 1 to 10 shown below. The thus-obtained mixtures each was fed to a 65-mm extruder to form a 0.7 mm thick external semiconductive layer together with a 0.7 mm thick internal semiconductive layer and a 4 mm thick crosslinked polyethylene insulater on an annealed copper twisted wire conductor having a cross sectional area of 150 mm2 by extrusion coating using a common head.
Then, the coated product was heated at 230C for crosslinking to manufacture an electric power cable insulated with a crosslinked polyethylene. The cross-linked polyethylene insulating layer was formed using a composition comprising 100 parts by weight of low density polyethylene (having a density of 0.920 g/cm3 and a melt index of 1.0 g/10 min), 2.5 parts by weight of dicumyl 20 ~ peroxide as the crosslinking agent and 0.25 parts by weight of 4,4'-thio-bis(3-methyl-6-tert-butylphenol). The temperature of the extruder was set in the direction from the feeding zone to the metering zone, as follows:
Cl=100C, C2=110C, C3=115C, and the die temperature of 120C.
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Ethylene-vinyl acetate copolymer 100 parts (containing 19~ of vinyl acetate;
with melt index of 2.5 g/lO min) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6 tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)ben2ene 0.5 parts Furnace carbon black (with arithmetic mean 60 parts particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 m~/100 g) Ethylene-vinyl acetate copolymer 100 parts (containing 25% of vinyl acetatei with meIt index of 3.0 g/10 min) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 part :
1,3-Bis(tert-butylperoxyisopropyl)benzene o.~ parts Furnace carbon black: (with arithmetic mean 60 parts particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 m~/lOO g) : .
Ethylene-vinyl acetate copolymer 100 parts (containing 28% of vinyl acetate;
with melt index of 6.0 g~10 min) ;` :
13~7~
1 Paraffin wax (melting point of 57.3C) 1 part 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) l part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~, iodine adsorption of 51 mg/g; and DBP oil absorption of 124 me/100 g) 1o EXAMPLE 4 Ethylene-vinyl acetate copolymer lO0 parts (containing 28% of vinyl acetate;
with melt index of 6.0 g/lO min) Paraffin wax (melting point of 57.3C) 10 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) l part 1,3-Bis(tert-butylperoxyisopropyl)ben~ene 0.5 parts Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 m~/lO0 g) EX~MPLE 5 Ethylene-vinyl acetate copolymer lO0 parts :(containing 28~ of vinyl acetate;
with melt index of 6.0:g/lO min) Paraffin wax (melting point of 57.3C) 20 parts 4,4'-Thi.o-bis(3-methyl-6-tert-butylphenol) 1 part 1, 3-Bis ( tert-butylperoxyisopropyl)benzene 0.5 parts . .
.
i3~7~0 1 Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 m~/100 g) Ethylene-vinyl acetate copolymer80 parts (containing 28~ of vinyl acetate;
with melt index of 6.0 g/10 min) Styrene-modified ethylene-vinyl acetate20 parts copolymer (containing 50% of styrene and 17~-of vinyl acetate) Paraffin wax (melting point of ~7.3C)5 parts 4,4' ~Thio-bis ~ 3~methyl~6~tert~butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic mean 80 parts particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 m~/100 g) Ethylene-vinyl acetate copolymerB0 parts (containing 28% of vinyl acetate;
with melt index of 6.0 g/10 min) Styrene-modified ethylene-vinyl acetate20 parts copolymer ~containing 50~ of styrene and 17~ of vinyl acetate) Paraffin wax (melting point of 57.3C)5 parts 131 7 ~ 3 ~
1 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic mean 60 parts particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 m~/100 g) Acetylene black (with arithmetic mean 20 parts particle size of 42 m~; iodine adsorption of 70 mg/g, and DBP oil absorption of 145 m~/100 g) Ethylene--vinyl acetate copolymer 60 parts (containing 28% of vinyl acetate;
with melt index of 6 g/10 min) Styrene-modified ethylene-vinyl acetate 40 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) Paraffin wax ~melting point of 57.3C) 5 parts 4,4'-Thio-his(3-methyl-6-tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl~benzene 0.5 parts Furnace carbon black (~ith arithmetic 80 parts mean particle size of 30 m~l; iodine adsorption of 53 mg/g; and DBP oil absorption of 13~ m~/lOOg) Ethylene-vinyl acetate copolymer 100 parts (containing 33% o~ vinyl acetate;
with melt index of 1 g/10 min) ~ 3 ~
1 Microcrystalline wax ~melting point 80C) 10 parts 4,4'-Thio-bis(3-methyl-6 tert-butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP
oil absorption of 133 me/loo g) Ethylene-vinyl acetate copolymer 80 parts (containing 33% of vinyl acetate; with melt index of 1 g/10 min) 15. Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) ~icrocrystalline wax (melting point 10 parts of 80C) 4,4'-Thio-bis(3-methyl-6-tert~butylphenol) 1 part 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption o~ 133 me/100 g) COMPARATIVE EX~MPLE 1 ~ :
Ethylene-vinyl acetate copolymer 100 parts (containing 60% of vinyl acetate;
with melt index of l0 to 20 g/10 min) :
: . ~ ?
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1 4,4'-Thio-bis~3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Acetylene black ~with arithmetic 70 parts mean particle size of 42 m~; iodine adsorption of 70 mg/g; and DBP oil absorption of 145 me/loo g) Vinyl chloride-Ethylene-vinyl acetate 100 parts terpolymer (containing 21% of vinyl acetate and 25% of vinyl chloride) 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Acetylene black (with arithmetic 70 parts mean particle size of 42 m~; iodine adsorption of 70 mg/g; and DBP oil absorption of 145 me/100 9 ) COMPARATIVE EXl~MPLE 3 Ethylene-vinyl acetate copolymer 100 parts (containing 28% of vinyl acetate;
with melt index of 6 g/10 min) Paraffin wax (melting point of 57.3C) 0.7 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-~is(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic ~0 parts mean particle size o~ 35 m~; iodine adsorption of 51 mg/g; and D~P oil absorption oE 124 me/100 g) ~ 3~5~
Ethylene-vinyl acetate copolymer100 parts (containing 28~ of vinyl acetate;
with melt index of 6 g/10 min) Paraffin wax (melting point of 57.3C) 25 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 35 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 124 me/100 g) Ethylene-vinyl acetate copolymer80 parts (containing 28~ of vinyl acetate;
with melt index of 6 g/10 min) ~ Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) Para~in wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxylsopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 45 parts mean particle size of 30 m~; iodine adsorption of 53 mg/g; and DBP oil absorption of 133 mejlOO g) ~3~7~
Ethylene-vinyl acetate copolymer 100 parts (containing 33% of vinyl acetate;
with melt index of 1 y~10 min) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size o~ 22 m~; iodine adsorption of 104 mg/g; and DBP oil absorption of 129 me/100 g) Ethylene-vinyl acetate copolymer 100 parts (containing 33% of vinyl acetate;
with melt index o~ 1 g/10 min) Paraffin wax (melting point of 57.3C) 5 parts ; . 4,4'-Thio-bis~3-methyl-6-tert-butylphenol)1 parts ~ 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arlthmetic 80 parts mean particle size of 29 m~; iodine adsorption of 70 mg/g; and DBP oil absorption of 127 me/100 g) Ethylene-vinyl acetate copolymer 100 parts (containing 33~ of vinyl acetate;
with melt index of 1 g/10 min) 13~7~
Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 34 m~; iodine adsorption of 51 mg/g; and DBP oil absorption of 103 me/100 g) Ethylene-vinyl acetate copolymer 80 parts (containing 33% of vinyl acetate;
~with melt index of 1 ~/10 min) Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing so% of styrene and 17~ of vinyl acetate) Para~fin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 30 m~; iodine adsorption of 220 mg/g; and DBP oil absorption of 178 me/100 g) Ethylene-vinyl acetate copolymer 80 parts (containing 33% of vinyl acetate;
with melt index of 1 g/10 min) ?
: ' :
~317~
1 Styrene-modified ethylene-vinyl acetate 20 parts copolymer (containing 50% of styrene and 17% of vinyl acetate) Paraffin wax (melting point of 57.3C) 5 parts 4,4'-Thio-bis(3-methyl-6-tert-butylphenol) 1 parts 1,3-Bis(tert-butylperoxyisopropyl)benzene 0.5 parts Furnace carbon black (with arithmetic 80 parts mean particle size of 43 m~; iodine adsorption of 44 mg/g; and DBP oil absorption of 115 m~/100 g) The compositions given above and the cables prepared using thereof were evaluated and the results are given in Table 1.
Evaluation were made according to the following.
Peel strenqth: Force necessary to peel the outer semiconductive layer off the cable was measured at room temperature according to the AEIC-CS5-82 standard.
Volume resistivity: Measured according to the AEIC-CS5-82 standard.
Tensile strenqth: The semiconductive layer peeled off the cable was measured following the JIS C-3005 standard. Those having the tensile strength of 1.0 kg/mm2 or more were evaluated 'good' and those lower than 1.O kg/mm2 were evaluated 'poor'.
1 Heat aqinq resistance; The semiconductive layer peeled off the cable was aged in a gear-oven aging tester at 135C for 7 days according to the IEC standardized method. Those maintaining both tensile strength and elongation in the range from 75% to 125~ of the initial values were evaluated 'good' and those showing values out of the above were evaluated 'poor'~
Mooney viscosity (MLl~4): Evaluations were made on semiconductive compositions at 120C. Those having values of 50 or less had good extrusion workability.
' '.
~3~7~
~'o _ _ _ _ -o o _ o _ _ _ ~ _ . -o __ _ ~ ~ ~r ~ t~ N ~r 1~1 ~r ~ ~r 1` ~ IS) t'`l u~ ~ Ll~ tr~ ~ ~I
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~ td ~ ~ ~ ~:5 ~ ~ ~ ~:5 ~ ~ S~ ~ ~ ~ ~ ~ ~ r~5 ~ ~
~c ~ g g g g g g g g o 8 8 g 8 g 8 8 g g g 8 ~.~ 1:~ C~l ~ I:T~ ~ ~ CJ IJ~ U tl ~ ~J Q ~J ~J Cl' ~ ~ ~
tl~l:r _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ a~
~, ~ ~ ~ ~ ~ ~ ~ ~ ~ '~:5 ~ ~ ~ ~ ~ ~ ra ~ g 8 g o g g g g $ g g g g o g 8 g g g g E~u~ ~ ~ ~ ~ ~ ~ ~J ~ U :r ~ ~J ~:r ~ ~ ~ ~ 8~ ~
~ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ ~ _ . _ n '1 ~ ~7 _1 ~ ~ _~ O O ~ rl r-l _~ ~1 ~ r ~r ~ ~r o u~
~ o O o o o o o o o o o o o o ~ o o o o o O V~ ~1 ~1 r-l ~ ~1 ~1 ~1 ~1 r-1 ~1 ~1 r-l ~ ~1 ~1 ~1 ~1 ~1 ~1 ~ ~ X X X X X X X X X X X X X X X X X X X X
E~ _ r~ d~ ~P r~ N N 00 N 1~ 1--~D N N ~r r` Il-) ~) 1~ ~
S _ __ _ _ _ _ _ _ _ ._ _ _ _ _ _ _ _ _ _ SS:
Il) 1~ N U~ C1~ N ~ a~ O C~ ~'1 t~l 00 ~1 Ln ~ If7 ~ In ~ ~ 1~ 00 V ~ ~ ~ ~ ~Y) t'`l N ~ ~1 N r-l ~1 ~1 ~C) N d' N N ~) ~r ~
_ _ _ _ _ _ _ _ _ _ _ _ _ ~ 1~ ~r u~ ~D 1- ~ ~ 'I
,1 ~ ~ ~r L~ ~D r~ co a~ ~ a~ I a) a) ~ ~ ~1 ~ ~ ~
Q r-l a) O a~ a) ~1 ~1 aJ ~1 O ~; ~ ~ ~i ~ ~ ~ E;
E3 X X ~ X ~ X X X X ~ ~ 1~ ~ ~ ~ w ~ ~ ~
r~ ~ ~ ~ ~ ~ E~ ~ ~ ~ ~ l~o o ~o ~o ~o ~o ~o o _ _ _ _ __ - - " I" ~ '~ " " " '~ '' _ _ _ _ _ _ _ _ _ _ _ ~3~7(3~
1 The samples of Example 1 to 10 of the present invention on the whole had good peeling strength, volume resistivity, mechanical stren~th, thermal resistance, and viscosity for the composition, except for the sample using an ethylene-vinyl acetate copolymer containing 19% by weight of vinyl acetate which showed a somewhat increased peeling strength.
Comparative Examples 1 and 2 used an ethylene-vinyl acetate copolymer containing 60% by weight of vinyl acetate and a vinyl chloride-ethylene-vinyl acetate terpolymer, respectively. In these cases, both mechanical strength and thermal resistance are insufficient.
Moreover, Mooney viscosity was so high that extrusion workability was deteriorated. Comparative Example 3 used less paraffin wax than the limit defined in the present invention. In such a case, peeling strength was increased and also the extrusion workability is somewhat damaged. Comparati~e Example 4, ~n the contrary, used more paraffin wax than the limit o~ the invention. In this case/ the heat aging resistance is insufficient.
Comparative Example 5 used furnace carbon black in an amount less than the limit of the present invention that the volume resistivity is too increased. Comparative Examples from 6 to 10 used furnàce carbon black in an amount out of the content range limited in the present _4 ' .
.
-~ ' 1 invention that volume resistivity or extrusion workability was deteriorated despite the good peeling property.
While the invention has been described in detail and with reEerence to specific embodiments thereof, it will be apparent to one skilled in the art that various changes and modifications can be made therein without departing from the spirit and scope thereof.
.
Claims (16)
1. An easily peelable semiconductive resin composi-tion comprising 100 parts by weight of ethylene-vinyl acetate copolymer-based polymer component, 1 to 20 parts by weight of waxy aliphatic hydrocarbon, and 50 parts by weight or more of furnace carbon black having an arithmetic mean particle size of 25 to 40 mµ, iodine adsorption of .40 to 60 mg/g, and DBP oil absorption (by JIS A method) of 120 to 150 ml/100 g.
2. An easily peelable semiconductive resin composi-tion as in Claim 1, wherein the polymer component com-prises only ethylene-vinyl acetate copolymer.
3. An easily peelable semiconductive resin composi-tion as in Claim 2, wherein the ethylene-vinyl acetate copolymer contains 20 to 55% by weight of vinyl acetate.
4. An easily peelable semiconductive resin composi-tion as in Claim 1, wherein the polymer component is a blend of ethylene-vinyl acetate copolymer (I) and aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer obtained by graft-copolymerization of aromatic vinyl monomer to ethylene-vinyl acetate copolymer (II).
5. An easily peelable semiconductive resin composi-tion as in Claim 4, wherein the ethylene-vinyl acetate copolymer (I) contains 20 to 55% by weight of vinyl acetate.
6. An easily peelable semiconductive resin composi-tion as in Claim 4, wherein the ethylene-vinyl acetate copolymer (II) contains 20% by weight or more of vinyl acetate.
7. An easily peelable semicondutive resin composi-tion as in Claim 4, wherein the aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer contains 5 to 60% by weight of aromatic vinyl monomer.
8. An easily peelable semiconductive resin composi-tion as in Claim 4, wherein the polymer component contains 95 to 50% by weight of ethylene-vinyl acetate copolymer (I) and 5 to 50% by weight of aromatic vinyl monomer-modified ethylene-vinyl acetate copolymer.
9. An easily peelable semiconductive resin composi-tion as in Claim 4, wherein the aromatic vinyl monomer is styrene.
10. An easily peelable semiconductive resin composi-tion as claimed in Claim 1, wherein the waxy hydrocarbon is paraffin wax.
11. An easily peelable semiconductive resin composi-tion as in Claim 1, wherein the waxy hydrocarbon is microcrystalline wax.
12. An easily peelable semiconductive resin composi-tion as claimed in Claim 1, wherein the composition further comprises an antioxidant.
13. An easily peelable semiconductive resin composi-tion as in Claim 12, wherein the antioxidant is 4,4'-thiobis(3-methyl-6-t-butyl-phenol).
14. An easily peelable semiconductive resin composi-tion as in Claim 1, wherein the composition further comprises a crosslinking agent.
15. An easily peelable semiconductive resin composi-tion as in Claim 14, wherein the crosslinking agent is 1,3-bis(tert-butylperoxyisopropyl)benzene.
16. An easily peelable semiconductive resin composi-tion as in Claim 1, wherein the composition further comprises an acetylene black in an amount such that the Mooney viscosity of the resulting composition is 50 or less.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP63075743A JPH01246708A (en) | 1988-03-29 | 1988-03-29 | Readily exfoliative semiconducting resin composition |
| JP75743/88 | 1988-03-29 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1317050C true CA1317050C (en) | 1993-04-27 |
Family
ID=13585066
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000577055A Expired - Fee Related CA1317050C (en) | 1988-03-29 | 1988-09-09 | Easily peelable semiconductive resin composition |
Country Status (5)
| Country | Link |
|---|---|
| US (1) | US4933107A (en) |
| EP (1) | EP0334992B1 (en) |
| JP (1) | JPH01246708A (en) |
| CA (1) | CA1317050C (en) |
| DE (1) | DE3852541T2 (en) |
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| US5230878A (en) * | 1989-10-02 | 1993-07-27 | Tokai Carbon Co., Ltd. | Carbon black for tire tread rubber |
| JP3029204B2 (en) * | 1990-04-16 | 2000-04-04 | 旭化成工業株式会社 | Highly conductive polyoxymethylene resin molded body |
| JP2886258B2 (en) * | 1990-05-08 | 1999-04-26 | 昭和キャボット株式会社 | Carbon black and rubber composition containing the same |
| US5236992A (en) * | 1991-11-18 | 1993-08-17 | Cabot Corporation | Carbon blacks and their use in rubber applications |
| JPH06104794B2 (en) * | 1992-03-27 | 1994-12-21 | 信越ポリマー株式会社 | Conductive composition for plastic coating |
| US5472639A (en) * | 1993-08-13 | 1995-12-05 | The Dow Chemical Company | Electroconductive foams |
| US5877250A (en) * | 1996-01-31 | 1999-03-02 | Cabot Corporation | Carbon blacks and compositions incorporating the carbon blacks |
| US5770257A (en) * | 1996-08-01 | 1998-06-23 | Minnesota Mining And Manufacturing Company | Method for altering cable semiconductive layer |
| JP3551755B2 (en) * | 1998-04-03 | 2004-08-11 | 日立電線株式会社 | Easily peelable semiconductive resin composition and electric wire / cable |
| US6274066B1 (en) * | 2000-10-11 | 2001-08-14 | General Cable Technologies Corporation | Low adhesion semi-conductive electrical shields |
| US6491849B1 (en) * | 2001-01-22 | 2002-12-10 | General Cable Technologies Corp. | High performance power cable shield |
| US20050031883A1 (en) * | 2001-09-19 | 2005-02-10 | Masanori Sera | Wrapping film and shrink film each comprising butene polymer |
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| US7449247B2 (en) * | 2003-05-26 | 2008-11-11 | Du Pont-Mitsui Polychemicals Co., Ltd. | Olefin polymer compositions and easy-peelable sealants using the same |
| US7767299B2 (en) | 2005-04-29 | 2010-08-03 | General Cable Technologies Corporation | Strippable cable shield compositions |
| EP2195378B1 (en) * | 2007-09-25 | 2013-01-09 | Dow Global Technologies LLC | Styrenic polymers as blend components to control adhesion between olefinic substrates |
| US8287770B2 (en) | 2010-03-05 | 2012-10-16 | General Cable Technologies Corporation | Semiconducting composition |
| CN101891915A (en) * | 2010-07-06 | 2010-11-24 | 苏州市双鑫新材料科技有限公司 | Strippable semi-conductive shielding material for insulation of cross-linked cable |
| CN101891916A (en) * | 2010-07-06 | 2010-11-24 | 苏州市双鑫新材料科技有限公司 | Peroxide crosslinked type semi-conductive screen material for crosslinked cable conductor |
| EP2898515A4 (en) | 2012-09-19 | 2016-06-01 | Gen Cable Technologies Corp | Strippable semiconducting shield compositions |
| JP6347415B2 (en) | 2014-11-20 | 2018-06-27 | 日立金属株式会社 | Semiconductive resin composition and power transmission cable using the same |
| JP6558564B2 (en) * | 2015-03-13 | 2019-08-14 | 日立金属株式会社 | Power cable |
| JP6429123B2 (en) * | 2015-03-13 | 2018-11-28 | 日立金属株式会社 | Power cable |
| JP2016170994A (en) * | 2015-03-13 | 2016-09-23 | 日立金属株式会社 | Power transmission cable |
| JP6521362B2 (en) * | 2015-03-13 | 2019-05-29 | 日立金属株式会社 | Power transmission cable |
| EP3559960B1 (en) | 2016-12-21 | 2021-12-22 | Dow Global Technologies LLC | Curable semiconducting composition |
| US11479662B2 (en) | 2017-08-29 | 2022-10-25 | Dow Global Technologies Llc | Polyethylene composition with treeing retardants |
Family Cites Families (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| DE2548371A1 (en) * | 1975-10-29 | 1977-05-05 | Daetwyler Ag | ELECTRIC SEMI-CONDUCTIVE SHIELDING FOR POWERFUL CABLES AND COMMUNICATION CABLES WITH PLASTIC INSULATION |
| SE440709B (en) * | 1976-06-10 | 1985-08-12 | Asea Ab | IF USING AN EXTENSION MACHINE ON AN INSULATION OF NON-CIRCUIT OR CROSS-POLYTEN PROVIDED CABLES, APPLY A LEADING, REMOVABLE LAYER |
| JPS5325886A (en) * | 1976-08-21 | 1978-03-10 | Sumitomo Electric Ind Ltd | Brid ged polyolefine insulating hightension cable having outer semiconductor layers which can be treated off easily |
| JPS5662846A (en) * | 1979-10-29 | 1981-05-29 | Mitsubishi Petrochem Co Ltd | Semiconductive resin composition |
| DE3034747C2 (en) * | 1980-09-15 | 1985-01-17 | kabelmetal electro GmbH, 3000 Hannover | Process for the production of a polymer mixture containing carbon black and its use for electrical cables |
| JPS57126004A (en) * | 1981-01-30 | 1982-08-05 | Nippon Unicar Co Ltd | Semiconductive polyolefin composition and cable using same |
| US4399060A (en) * | 1981-02-10 | 1983-08-16 | E. I. Du Pont De Nemours & Co. | Semiconductive elastomeric composition |
| US4374227A (en) * | 1981-05-15 | 1983-02-15 | Union Carbide Corporation | Extruded gloss improvement in pipe blends with low pressure low density polyethylene |
-
1988
- 1988-03-29 JP JP63075743A patent/JPH01246708A/en active Granted
- 1988-09-09 CA CA000577055A patent/CA1317050C/en not_active Expired - Fee Related
- 1988-09-27 DE DE3852541T patent/DE3852541T2/en not_active Expired - Fee Related
- 1988-09-27 EP EP88115903A patent/EP0334992B1/en not_active Expired - Lifetime
- 1988-09-30 US US07/251,415 patent/US4933107A/en not_active Expired - Lifetime
Also Published As
| Publication number | Publication date |
|---|---|
| EP0334992A1 (en) | 1989-10-04 |
| DE3852541T2 (en) | 1995-05-04 |
| DE3852541D1 (en) | 1995-02-02 |
| US4933107A (en) | 1990-06-12 |
| EP0334992B1 (en) | 1994-12-21 |
| JPH0577123B2 (en) | 1993-10-26 |
| JPH01246708A (en) | 1989-10-02 |
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| Date | Code | Title | Description |
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| MKLA | Lapsed |